It’s as though Rosalind Hall is wielding a hand-held fan, pressing it against surfaces so that it buzzes in frictional complaint, without applying the necessary pressure to stop the blades entirely. It’s a delicate navigation of brinks and almosts – her saxophone lingers upon single notes and tilts them, ever so slowly, until they threaten to fall over. Her instrument throbs uneasily as overtones force their way into the frame, turning ovular drops of pure tone into snarls of dissonance. It’s an agonising sonic yoga routine; pitches bend into awkward poses and then hold them for as long as concentration, exhalation and muscle power will permit, the note wobbling like calves and biceps in convulsions of tension. Collapse is always a mere false step away.